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Large delayed plasma creatine kinase changes after stepping exercise
Author(s) -
Newham D. J.,
Jones D. A.,
Edwards R. H. T.
Publication year - 1983
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.880060507
Subject(s) - eccentric , creatine kinase , tenderness , medicine , endocrinology , eccentric exercise , muscle contraction , creatine , muscle damage , surgery , physics , quantum mechanics
Muscle changes have been examined in 16 normal subjects (eight female) after both a 20‐minute and a prolonged step test. Stepping differs from most exercise tests in that it involves eccentric contractions (negative work) in which the active muscle is lengthened. Plasma creatine kinase (CK), muscle force, contractile properties, and tenderness in the quadriceps were measured for up to 9 days after the exercise. Muscle tenderness was experienced only in the muscles that had performed eccentric contractions (i.e., stepped down). All subjects showed some early rise in CK (<400 IU/liter) but eight (both male and female) showed a much greater response (up to 34,500 IU/liter) which took a long time to reach peak levels (4–5 days after stepping). It is suggested that eccentric contractions involved in this form of exercise result in some particular form of muscle damage which, in susceptible subjects, may initiate changes giving rise to a large delayed release of muscle enzymes.